Chevron Phillips Chemical saw a process upset Sunday at its 667,000 mt/year Ethylene Unit No. 24 at its Sweeny olefins complex in Old Ocean, Texas, the company said in filing with state regulators Monday.
During the startup of the ethane/propane (E/P) treater there was excess pressure in the pump line which resulted in a relief valve opening to flare, the filing with the Texas Commission on Environmental Quality showed.
The flaring, which was expected to run through Monday, released 125 lb of ethylene, 9 lb of propylene, along with smaller volumes of other chemicals, the filing showed.
The 667,000 mt/year Ethylene Unit No. 24 appeared to be in working condition, a source with knowledge of operations said.
A company spokeswoman could not be immediately reached for comment.
The company operates three steam crackers at the Sweeny site with a combined ethylene production capacity of 1.94 million mt/year.
Platts assessed US ethylene at 25 cents/lb FD USG for May and June deliveries on Friday.
